1. Field of the Invention
The present invention relates to a vehicular battery pack device. More specifically, the invention relates to a battery pack device that is incorporated in a hybrid vehicle an electric vehicle.
2. Description of the Related Art
A structure is known in which a cooling air discharge outlet of a power unit is opened on the front side of a rear bumper (refer to JP-A-2010-285151, for example). In this structure, the space interposed between the cooling air discharge outlet and the rear bumper is open on the bottom side. Therefore, liquid such as rain water or cleaning water may flow into the power unit through the cooling air discharge outlet to wet it while the vehicle is running or being washed. Furthermore, while the vehicle is running, travel wind may go into the space between the power unit and the rear bumper and impair the flow of cooling air around the cooling air discharge outlet, possibly lowering the performance of the cooling of a battery module that is incorporated in a battery pack. A structure in which a bottom cover is provided under the bottom surface of a vehicle to prevent entrance of travel wind is known (refer to JP-A-2009-96438, for example).